London
Big Yellow, Staples Corner
The scheme comprises a new multi storey self-storage building formed with a braced steel frame supported on reinforced concrete substructure. The building had a six-storey mezzanine supported off the ground floor slab across the full building footprint. Evolve were appointed to design the shell of building.
The development involved complex structural coordination due to the complex geometry. In addition, the site was heavily constrained by adjacent infrastructure including the River Brent, a Network Rail viaduct and a National Grid tunnel beneath the site. Ground conditions associated with the historic Brent Reservoir also required innovative foundation solutions. The project also incorporates flood mitigation strategies, sustainable material procurement targets and embodied carbon assessments in line with modern environmental design standards.
Client: Big Yellow Self Storage Company Ltd
Location: Staples Corner, North Circular Road, London NW2 1LY
Sector: Industrial
Architect: Mountford Pigott
Structural Engineers: Evolve
MEP Engineer: TFT
Image Credit: Mountford Pigott
The Challenge
The site presented a series of significant engineering constraints that required careful coordination between the design team, contractors and third-party stakeholders. Historically, the site formed part of the Brent Reservoir before being reclaimed and redeveloped, resulting in very loose made ground and alluvium extending up to 7.5m below ground level. Additional challenges included perched groundwater, near-surface obstructions, high volume change soils and aggressive ground conditions for buried concrete.
The project also sits adjacent to the River Brent and a Network Rail viaduct, while a National Grid tunnel runs approximately 20m from the site boundary. These conditions imposed strict requirements for flood mitigation and construction sequencing.
The complex architectural form further increased the engineering challenge, with diagonal roof spans, projecting façades, large glazed areas and column-free zones requiring a carefully coordinated structural solution.
The Solution
To address the challenging ground conditions, Evolve engaged specialist ground improvement sub-contractors to provide Controlled Modulus Columns (CMC) to improve the bearing capacity of the site and allow the use of reinforced concrete pad foundations and ground beams. A ground bearing slab on CMC’s was also employed to accommodate heavy mezzanine leg loads and operational flexibility across the building footprint.
The superstructure was designed as a braced steel frame with fixed-base columns, transfer beams and roof girders working together to provide stability while maintaining open, flexible storage spaces. Long span members were precambered to take the dead load deflection out and reduce steel tonnages.
Flood resilience formed a key part of the civil engineering strategy, with floor levels raised above predicted flood levels and flood compensation measures introduced adjacent to the River Brent.Evolve also acted as the Contractor’s Engineering Manager (CEM) and the Contractor’s Responsible Engineer (CRE, Design) which involved managing design, construction and safety throughout the works to identify and mitigate risks to Network Rail’s asset.
